Embodiments of the invention relate to a method and device for controlling a motor vehicle in the presence of disturbances such as those caused by a trailer or semi-trailer.
Stability is a concern for a vehicle towing a trailer, especially when the vehicle towing the trailer is traveling at high speed or making a turn. Since the trailer significantly affects the dynamics of the towing vehicle, many control systems use techniques to improve the stability of the towing vehicle especially when a trailer is present. For example, systems such as anti-lock braking systems (“ABS”), traction control systems (“TCS”), and vehicle dynamics control (“VDC”) systems are configured to perform a variety of functions that impact the vehicle and the trailer in order to improve stability. Furthermore, the towing vehicle can better control its transmission if the presence of a trailer is known to a control unit in the vehicle.
When towing a trailer, vehicles generally need additional hardware including a hitch articulation angle sensor to detect the behavior of the trailer, and to activate the vehicle's brake or engine control in response to trailer activity. In some other cases, signals from an electronic stability program (“ESP”) are used for a detection of trailer oscillation. Once a trailer oscillation has been detected, the brake or the engine control is applied. However, once the trailer oscillation has started, any application of brake or engine control may be too late to be effective. Furthermore, since these controls are based on a heuristic approach in which only a portion of the vehicle dynamics is considered (instead of specific trailer dynamics), brake and engine controls can be unreliable.